Life Sciences Commons^™

Transport And Fate Of Phosphorus In The Nearshore Zone Of Lake Michigan, Nathan Van Ee

Theses and Dissertations

Bioavailable phosphorus loads exported to Lake Michigan from the Milwaukee and Sheboygan River Watersheds appear to have increased in the last 40 years despite meeting total phosphorus (TP) loading goals set by the Great Lakes Water Quality Agreement (GLWQA).Overall, bioavailability of P delivered from the Milwaukee and Sheboygan Rivers was highest during the warmer months, which coincides with the nearshore nuisance algae growth season. However, first order loss rates of SRP calculated during baseflow recession were also greatest during the summer, suggesting that increased river residence time during the summer could reduce export of bioavailable P. Observations of phosphorus partitioning …

Evaluating The Biological Activities Of Novel Histone Deacetylase Inhibitors (Hdaci) In Adherent And Nonadherent Tumor Cell Lines, Samer Alanani

Theses and Dissertations

Epigenetic dysregulations are linked to many human diseases including neurodegenerative disorders, immunodeficiencies, cardiac disease, and most notably cancer. Changes in the mechanisms of histone modifications have been recognized as hallmarks of carcinogenesis. One of these modifications is histone acetylation which is regulated by the activities of histone acetyltransferases (HATs) and histone deacetylases (HDACs). The reversible actions of these enzymes govern the acetylome and maintain its balance allowing for activation and repression of gene transcription. However, aberrant overexpression of HDACs in certain tumors is associated with decreased levels of transcription leading to tumor progression and survival. Hence, small-molecule histone deacetylase inhibitors …

Transcriptomics And Toxcast Data Identify Bioeffects In Zebrafish Embryos Exposed To Chemical Mixtures In An Effluent-Dominated Stream, Emma Meade

Theses and Dissertations

Wastewater treatment plant (WWTP) effluent-dominated streams provide critical habitat for aquatic organisms but also continually expose them to complex mixtures of pharmaceuticals and other contaminants of emerging concern (CECs) that can potentially impair growth, behavior, and reproduction. Limited toxicity data on the adverse biological impacts of in vivo exposure to these mixtures make it difficult to assess risk for aquatic organisms, particularly with respect to pharmaceuticals whose designed bioactivity often extends beyond conventionally monitored biological pathways. To address this knowledge gap, the goal of this thesis was to identify biomarkers of exposure to complex CEC mixtures relevant to specific chemicals …

Selection And Demography Drive Range-Wide Patterns Of Mhc Variation In Mule Deer (Odocoileus Hemionus), Rachel M. Cook

Theses and Dissertations

Variation at functional genes involved in immune response is of increasing concern as wildlife diseases continue to emerge and threaten populations. The amount of standing genetic variation in a population is directly associated with its potential for rapid adaptation to novel environments. For genes in the major histocompatibility complex (MHC), which are crucial in activating the immune response and which have extremely high levels of polymorphism, the genetic variation has been shown to be influenced by both parasite-mediated selection and historical population demography. To better understand the relative roles of parasite-mediated selection and demography on MHC evolution in large populations, …

Molecular Weight Distributions And Size-Dependent Composition Of Dissolved Organic Matter In The Aquatic Continuum, Hui Lin

Theses and Dissertations

Dissolved organic matter (DOM) in aquatic environments is one of the most important carbon reservoirs in global carbon cycling. The molecular weight of DOM is strongly related to a great number of biogeochemical reactions, influencing ecological functions and the fate of bioactive elements in aquatic ecosystems. A new technique coupling flow field-flow fractionation with fluorescence excitation-emission matrix (EEM) and parallel factor (PARAFAC) analysis was developed to elucidate the variations in DOM composition and optical properties with molecular weight in the individual samples and their changes along the aquatic continuum. Based on the novel coupling technique, variations in DOM characteristics were …

Health Goals For Perfluorinated Alkyl Substances (Pfas): A Review Of Branched Isomers, The Role Of Industrial Sources, And The Implications Of Pfas In Biosolids On End-Of-Life Disposal Methods, Katarina Schulz

Theses and Dissertations

Per- and polyfluorinated alkyl substances, or PFAS, have been used for over half a century, but have become an emerging contaminant of significant concern due to their newly found widespread occurrence and recalcitrance in the environment, their tendency to bioaccumulate, and the health effects now associated with a very low level of exposure. Many gaps in knowledge remain about the fate of these chemicals in the environment and the extent of their impacts on biota. This thesis aims to fill some of the recognized gaps in knowledge: differences between linear and branched isomers of PFAS, predicting the presence of PFAS …

Part I: Development Of Small-Molecule-Based Probes For The Vitamin D Receptor; Part Ii: Development Of A Scalable Manufacturing Process For Orcein Dye, Tania Roseann Mutchie

Theses and Dissertations

PART I:The vitamin D receptor (VDR) is a ligand-dependent transcription factor and member of the nuclear hormone receptor superfamily. VDR is expressed in the epithelia of endocrine organs, digestive system, bronchi, kidneys, and thymus, as well as being present in leukocytes and bone cells. Cell proliferation, cell differentiation, and immunomodulation, along with calcium and phosphate homeostasis, are all processes regulated by the receptor. Within the cell, VDR can be membrane-bound or located in the nucleus. Nuclear localization of VDR transpires following the binding of vitamin D metabolites, the most active of which is 1α,25-dihydroxyvitamin D3 (calcitriol). Within the nucleus, interactions …

Autumn Tree Phenology In Northern Wisconsin: Humans Versus Photographs, Trevor Iglinski

Theses and Dissertations

Ecosystem primary productivity halts when plants go dormant, and so the timing of dormancy as it relates to autumn phenology has been a focus of much interdisciplinary research. While monitoring plant phenology has its roots in directly observing specimens, digital sensors along with modern methods have also become a mainstay in phenology. Results from different methods often vary, so there is still a need to better understand how digital cameras record autumn phenology, especially in comparison with ground-based observations (Keenan et al. 2014). This study compared autumn phenology derived from direct ground observations with upward-facing fisheye photography, in the context …

Predicting Factors Of Re-Hospitalization After Medically Managed Intensive Inpatient Services In Opioid Use Disorder, Brian Kay

Theses and Dissertations

IntroductionOpioid use disorder has continued to rise in prevalence across the United States, with an estimated 2.5 million Americans ailing from the condition (NIDA, 2020). Medically managed detoxification incurs substantial costs and, when used independently, may not be effective in preventing relapse (Kosten & Baxter, 2019). While numerous studies have focused on predicting the factors of developing opioid use disorder, few have identified predictors of readmission to medically managed withdrawal at an inpatient level of care. Utilizing a high-fidelity dataset from a large multi-site behavioral health hospital, these predictors are explored.

MethodsPatients diagnosed with Opioid Use Disorder and hospitalized in …

Investigation Of G Protein-Coupled Receptor Quaternary Structure Through Fluorescence Micro-Spectroscopy And Theoretical Modeling: Interdependence Between Receptor-Receptor And Receptor-Ligand Interactions, Joel David Paprocki

Theses and Dissertations

Proteins are of high interest in biophysics research due to the important roles they play within cells, such as sensing of chemical (ions and small molecules) and physical (e.g., light) stimuli, providing structure, transporting ions/molecules, signaling, and intercellular communication. The studies described in this dissertation focus on a particular type of membrane proteins known as G protein-coupled receptors (GPCR), which play a key role in cellular response to external stimuli. We used the sterile 2 α-factor mating pheromone receptor (Ste2), a prototypical class D GPCR present within Saccharomyces cerevisiae (baker’s yeast). Ste2 is responsible for initiating the second messenger signal …

Structure & Function Of Enzymes In Two Uncharacterized Gene Clusters From Pseudomonas Brassicacearum & Streptomyces Griseofuscus, Lamia Tabassum Badhon

Theses and Dissertations

Pyridoxal 5’-phosphate (PLP)-dependent enzymes harness this versatile cofactor to catalyze a variety of reactions including transamination, decarboxylation, racemization and various elemination/subsitution reactions. Several years ago, a new class of PLP-dependent enzymes was discovered that uses PLP and molecular oxygen to catalyze the 4-electron oxidation of L-arginine to 4-hydroxy-2-ketoarginine. Work with the prototypical enzyme of this class, MppP from Streptomyces wadayamensis (SwMppP), showed that the dioxygen consumed during the reaction is reduced to hydrogen peroxide, and that the hydroxyl group installed in the product derives from water. Thus, SwMppP is an L-arginine oxidase, and not an oxygenase. This was surprising given …